Selective calling-key for party-lines.



No. 680,8.8I. Patented Aug. 20, 190i. F. R. McBERTY. SELECTIVE CALLING KEY FOR PARTY LIN 2 Shook-Sheet l.

I j Z flaw? $1M Vfz'fness es:

No. 680,88I. Patented Aug. 20, I90l. F. R. McBERTY. SELECTIVE CA LLING.KEY FOR- PARTY LINES.

(ppliu ion filed J. 6, 1900.)

2 Sheeta-Sheet 2,

(lo lodol.)

M MW- UNITED STATES PATENT OFFICE.

FRANK R. MOBERTY, or EvANs'roN, ILLINOIS, nssrenon TO THE WESTERN ELECTRIC COMPANY, or CHICAGO, ILLINOIS.

SELECTiVE CALLlNG.-KEY FOR PARTY-LINES.

SPECIFIGATIGN forming part of Letters Patent No. 680,881, dated August20, 1901.

Application filed January 6, 1900. Serial No. 532. (No model.)

1o Myinvention relates particularly to systems of telephoneexchange in which partylines are employed.v In such systems it is usual to place four stations upon one telephone-circuit, the bells of two stations being connected with one limb of the circuit and the bells of the other two stations being con-' nected with the other limb thereof, each bell being in a normally-grounded branch. The

- bells are polarized and adapted to respond to currents of the proper direction.

My invcntion'relates more particularly to the operators selective calling-key, one such key being combined with a set of connecting cords and plugs. Each pair of cords will be a 5 provided with the usual calling key, and when the calling-key of any particular pair of cords is pressed connection is made with the common or selective calling-key. In case the pair of cords is used for making connection with a. line not a party-line the contacts of the selective calling-key being in their normal position will permit alternating current from the generator to be thrown to the line .called for. Thus the operation of an indi-' vidual calling-key serves to transmit an at ,ternating current over the line. If, however,

a subscriber upon a party-line is being called, the selective calling-key must be brought into m service to throw current of the proper polar- 40 ity onto the limb of the telephonecircuit with which the bell of the subscriber wanted is connected.

My invention relates more particularly to the construction of the selective calling-key and the combination thereof with the other parts of the apparatus. I Stated generally, the selective calling-key consists of four double sets of contact-springs grouped about a central standard or axis, upon which is mounted by a ball-and-socket joint the operating-lever, saidlever carrying.

four radial arms, which arms are adapted of springs, according to the direction in which the lever is moved, to wedge or move the springs, and thus to make and break the con:

each to be inserted between a particular set tacts of the diflerent sets of keys as required. The lever is provided with a handle adapted to be moved sidewise in either of four directions to bring the proper one of the radial arms or wedges against a particular spring or set of springs.- An escutcheon carried by the handle of the lever when moved serves to prevent dust from getting into the contacts of the keys. When the lever is in its upright position, the several sets of keys will be closed and the generator of alternating current will be connected through the said contacts, so that when the key of any'particular set of cords is depressed the alternating current may be thrown to line, if desired.

My invention is illustrated in the accompanying drawings, in which- Figure l is a plan view of my selective calling-key. Fig. 2isa side elevation thereof. Fig. .3 is a side view, partially in section, certain parts being removed. Fig. 4 is a plan view of the sets of keys as seen from line 2 2, Fig. 2. Fig. 5 is a view as seen from section-line 3 3, Fig. 3; and Fig. 6 is a diagram illustrative of a four-party-line circuit and the connections of the operators apparatus with my selective calling-key.

Like parts are indicated by similar characters of reference throughout the different .fig-ures.

I will first refer to the party-line circuit shown in Fig. 6. This circuit consists of two limbs a b. The bell ct ofstation 1 is connected in a grounded branch with said limb a and adapted to respond to positive current. The bell a of station 2 is connected in like manner with said limb a but adapted to respond only to negative current. Bell 1) of station 3 is connected in a similar way with limb b, as well as hell b of station 4, bell b being-polarized to respond to current and bell b to respond to current. A source of current 0 is provided at the central office, and heretofore it has been common to send current of proper polarity from such a source over the different limbs a b of party-lines of the character described. 1 The generator dis an ordinary source ofalternating ,cnrren-t. When the ordinary k'eye isoperated or pressed, the springse e are thrown uporr the contacts leading to the generator d through the several contacts of the selective callingkey when the calling-key is in its normal po- 'sition.

In such 'case the calling-key is for the time ignored, the plug'c being inserted into some single party-line, upon which the subscribers apparatus is adapted to respond I in the usualrway to alternating currents. The diiferent setsofkeys f f f f may be considered its corresponding,

party-line.

As shown in detail in Figs. '1 1505311089. lective calling-key consists of vfour double f. f f 3 f arranged centrally sets of'springs about the standard or axis 9. Upon this standard 9 is mounted the lever g, having the ball-and-socket joint 9 and carrying the radial arms or wedges h k ll it. lever is in its normal position.that is, up- 5 right, as shown in Fig. 2-the contacts of the different springs will be as illustratedin Fig. When it is desired to open. the normal contacts of a particular set of springs for the piirpose of throwing calling-current onto the line, it is only necessary to tilt the lever in,

the direction required. For example, as shown in Fig. 3, the arm or wedge h'is thrust between the springs z i", in which casethe spring 7 will be thrown upon the anvil or contact k and the spring 2" upon the anvil or contact Zc'.- Thus in this particular instance the plug e beinginserted in spring-jack Z correspondingthereto current-willbe sent over limb a and passing through bell of of station 1 will operate the same. In like manner the lever may be thrown to operate the keys 1" J- f to ring the bells at the other stations 2, 3, and

410i the party-line as desired.

The escntcheon m is placed over the convex plate m and is held against said plate, so as to prevent dust from entering, by means of the spring m Having thus, described my invention, I

. claim as new, and desire to secure by Letters Patent, the following:

1. The combination with the double sets of contact-springs f f f of the centrallyplaced standard or axis and the lever pivotally mounted on said of said sets of springs may be changed on tiltrespectively, with the several stations 1, 2, 3,, and 4 of the When the a standard, said lever car-' rying radial arms or wedges 7t h h h, one for each set of springs; whereby the contacts 1 the arm. or wedge of a particular set of springs being adapted to be forced between the members of such set to wedge the same apart and change thecontacts thereof onv tilting the lever in the proper direction.

3. The combination with a number of sets of contact-springs arranged around a central standard, of an operatinglever pivotally m'ountedon said standard and adapted to be tilted angularlyin different directions to actuate any desired set of contact-springs, a

convex platem through which the handle of the lever is. passed, having an opening in whichsaid'lever may be moved to and fro,

and a convex escutcheon m carried by the lever and fitting over said opening in the convex plate, substantially as set forth.

4..-Th'e selective calling-key consisting of vertically placed switch springs grouped about an axis or standard, in combination with wedges of insulating material adapted tobe moved bya common lever, the center of pressure or greatest resistance of the springs to the wedges when thrust between them being above the pivotal bearing of the support for the wedges; whereby the resistance of the springs of any'set when a wedge is forced between the same aids in keeping the support for the wedges against its bearing, substantially as and-for the purpose specified.

5. The pivoted operating-lever with four radial arms therefrom at right angles to each other and to the lever, carrying-wedges, in combination with the four sets of switch 'springs, one adapted to be operated byge ach wedge, and the. central standard g supporting the lever at the center of the four arms, whereby two wedge-arms in alinement with one another rotate asa shaft between the corresponding switch-springs while a wedge at right angles thereto is thrust between the springs to operate them, substantially as set forth.

In witness whereof I hereunto subscribe my name this 11th day of November, A. D. 1899.

Witnesses:

GEORGE P. BARTON, JAY. W. SKINKLE.

. FRANK. R. MGBERTY.

Corrections in Letters Patent No. 680,881.

shonld'be inserted to indicate the different and k is to indicate the anvils or contacts; and that the said Letters Patent should therein that the. same may conform to the record of the It is hereby certified that in Letters Patent No. 680,881, granted August 20, 1901, upon the application of Frank R. McBerty, of Evanston, Illinois, for an improvement in Selective Calling-Keys for Party-Line s, errorsappear requiring the following corrections The drawings forming a part of said patent should have. been corrected,- as directed by the patentee in an amendment duly filed before the issne of the patent, as follows: Fig. 1, reference fignres"1,.2,3, 4 should 'readz, 1, 4, 3', respectively; Figs. 2 and3, reference letters f f should read f f; Figs. 2' and 3, reference letters,h If should "read h" h"; 3, reference letter i should be stricken out, and the spring on the left-hand "of the drawing should be indicated by i; erence letters i i as applied to the right-hand set of springs should be stricken out and inserted to indicate the left-hand set, and letters 11' h h I? should read h? h hli, respectively, and Fig. 5, reference letters '5' k should be stricken out, and f f f f I sets of keys; ii to indicate the springs,

be readwith these corrections case in the Patent Office.

Signed, eo'untorsigned, and sealed this. 10th day of September, A. 1)., 1901.

[SEAL] F. L. CAMPBELL,

Aegis-Jam Secretary of the Interior.

Countersigned F. I. ALLEN,

Commissioner of Patents.

Fig. 4, ref- Corrections in Letters Patent No. 680,88l.

It is hereby certified that in Letters Patent No.6SO,881,g1-antedAugust 20,1901,

upon the application of Frank R. McBerty, of Evanstont, Illinois, foran improvement in Selective Calling-Keys for Party-Lines, errors appear requiring the following corrections: The drawings forming a part of saidpatent should havebee'n corrected, as directed by the patentee in an amendment duly filed before the issue of the patent, as follows: Fig. 1, reference figures 1,.2, 3, 4 should readfl, 1,4, 8', respectively; Figs. 2 and3, reference letters f f should read f f Figs. 2' and 3, reference letters.h If should read h h"; 3, reference letter i should be stricken out,

' and the spring on the left-hand of the drawing should be indicated-by t"; Fig. 4, reference letters i i as applied to the right-hand set of springs should he stricken out and inserted. to indicate the left-hand set, and letters k I? h h? should read h? h iii-k respectively, and Fig. 5, reference letters i k, should be stricken out, and f f f f should 'be inserted to indicate the different sets of keys; it" to indicate the springs, and k k to indicate the anvils or contacts; and that the said Letters Patent should he read with these corrections therein that the. same may conform to the record of the case in the Patent Office.

Signed, countcrsigned, andsealed this 10th day of September, A. 1)., 1901.

[SEAL] F. L. CAMPBELL, I I Aesisant Secretary of the Interior. Coiintersign ed F. I. ALLEN,

. Commissioner of Patents. 

